1. Field of the Invention
This invention relates generally to an automobile steering column interconnector. More specifically, the present invention relates to an automobile steering column interconnector that electrically unites a rotatable air bag assembly with a stationary sensor using one or more conductors that are simultaneously associated with the interconnector hub and housing. The conductors are preferably metallic rings that electrically unite a stationary interconnector housing with a rotatable interconnector hub.
An increasing number of automobiles have air bag crash systems. The air bag crash system typically includes an air bag located on the steering wheel facing the driver. The air bag must be in continuous electrical connection with one or more sensors in the car body. The sensors provide an electrical signal to the air bag crash assembly which instantly inflates the air bag in the event of a crash.
Accordingly, there is a need for an electrical connection between the rotatable portion of the air bag assembly which is mounted in the steering wheel and the sensors which are in a stationary position in the car body. Electrical connections between rotatable and stationary parts of a steering wheel are well known. Typically, a coiled electrical conductor, known as a clock spring, is united at one end to a stationary housing and at the other end to a rotatable hub. Rotation of the hub causes the coiled electrical conductor to tighten and to loosen much like a clock spring without jeopardizing the electrical connection.
There is a risk with the coiled electrical conductor that it will fail due to over rotation of the steering wheel or through overuse. As a result, elaborate methods are used to ensure that the clock spring interconnectors do not over rotate and that the interconnectors are installed in their proper initial orientation. These measures are costly and add additional parts to the clock spring devices which can fail.
2. Description of the Art
Automobile steering column interconnectors referred to as "clock springs" are well known in the art. Examples of automobile clock springs are shown in U.S. Pat. Nos. 5,061,195 and 4,722,690. Automobile clock spring interconnectors electrically unite a stationary sensor in a car body with an automobile air bag located in a steering wheel via a spirally wound coil of electrically conductive tape. An electrical signal from the sensor passes to the clock spring through the electrically conductive tape to actuate the air bag in the steering column.
Air bag interconnectors that do not use coiled conductive tape or wire windings to create an electrical pathway are also known in the art. For example, U.S. Pat. No. 5,009,604 describes an interconnector assembly that uses circular, resilient electrically conductive contact members to complete the electrical path between the interconnector housing and hub.
Finally, U.S. Pat. Nos. 4,650,266 and 4,372,633 disclose an apparatus useful in satellites for transferring high electrical currents. The apparatus disclosed in each of the patents includes a plurality of horizontal rolling rings that act in unison to transfer an electrical current from a rotatable element to a stationary element.